A double-blind, placebo-controlled, parallel-group pilot study of milnacipran for chronic radicular pain (sciatica) associated with lumbosacral disc disease.

OBJECTIVE

The current study investigates whether milnacipran, an equipotent serotonin-norepinephrine reuptake inhibitor, is effective in reducing chronic radicular pain in patients (N = 11) with lumbosacral disc disease.

METHOD: This study is a 10-week randomized, parallel-group, double-blind, placebo-controlled trial of milnacipran (100-200 mg/d, dosed twice a day). Subjects (enrolled from October 2010 to September 2011 through the Duke University Pain and Palliative Care Clinic, Durham, North Carolina) included patients with radiologically confirmed disc disease with nerve root compression. The primary outcome measure was radicular pain measured by visual analog scale score (VAS-Rad); patients were asked to specifically rate radicular pain ("shooting or electrical or prickly pain in 1 or both legs"). Secondary outcome measures included nociceptive low back pain by visual analog scale (VAS-Noc), Oswestry Low Back Pain Disability Questionnaire, Neuropathic Pain Questionnaire, Medical Outcomes Study (MOS) 36-Item Short-Form Health Survey, Beck Depression Inventory, and State-Trait Anxiety Inventory. Between-group changes in outcome measures between baseline and endpoint were analyzed using Mann-Whitney U nonparametric measure of central tendency.

RESULTS

Milnacipran treatment yielded statistically significant reduction in radicular pain (VAS-Rad, P = .01) and nociceptive low back pain (VAS-Noc, P = .04) compared to placebo. No statistically significant between-group differences were observed in the other secondary outcome measures.

CONCLUSIONS

In this small pilot study, milnacipran treatment was associated with reduction in radicular and nociceptive low back pain in patients with lumbosacral disc disease. Larger studies of milnacipran in this population are warranted.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01777581.